Disk-brake lining backing plates supported symmetrically in a well of a fixed-caliper disk brake, which comprise cuboidal brake pads, are well known. It is primarily passenger cars have fixed-caliper disk brakes, wherein, for forward and reverse travel, the friction linings rest under compression, in each case on the exit side, against symmetrically radially oriented flanks of the well in the brake caliper housing and are correspondingly guided in the well (Bremsenhandbuch [Brake Handbook], Breuer/Bill; 3rd edition 2006, page 97, FIGS. 7-11, ISBN-13 978-3-8348-0064-0). With a very compact and stiff construction, however, the useful friction area is limited and the thermal balance is likewise susceptible of improvement.
Symmetrical disk brake linings that have a friction area which is enlarged in the circumferential direction have been disclosed, wherein lateral retaining protrusions with eyes to receive pins fixed to the housing are provided beyond the center of the backing plate, on each end face of the backing plate, being offset radially inward and being of identical height (i.e. at an identical distance from an axis of rotation of the wheel). In this case, the tangential forces are always borne by the entry-side pin, and the exit-side pin is used as a rotation lock as per U.S. Pat. No. 8,517,152 B2/WO 2005/064 188 A1. The advantage of this brake-lining and caliper design is the stiffness thereof, i.e. performance capacity and also thermal robustness. This symmetry of the backing plate is often preferred, for esthetic reasons among others. However, the noise characteristics of this backing plate mounting are regarded as susceptible of improvement, especially in the case of a change in the direction of rotation.
In a fully corresponding way, FIG. 13 of EP 2 873 886 A2 shows a backing plate having retaining protrusions that project laterally on both sides and have eyes for receiving pins, although these are arranged at different heights. At the core of this development is the general aim of imparting a radially inward-turning torque to a disk brake lining both for forward and for reverse travel. For this purpose, a description is given not only of a changeover between pull-type disk brake lining mounting during forward travel and push-type disk brake lining support during reverse travel but also of three points of support for supporting the disk brake lining in the brake, which act in various combinations on the backing plate. The NVH behavior appears to be susceptible of improvement since rattling noises during a change in the direction of rotation may be found objectionable.
Owing to ageing, harsh operating conditions, possibly in combination with neglected maintenance, fixed-caliper brakes that are operating in a fundamentally satisfactory manner may namely give rise to problems in respect of comfort and associated braking noises (brake squeal). Corresponding phenomena relating to comfort are described by the vehicle drivers or test drivers by terms such as “rubbing”, “grinding”, “groaning” and also squeal or the like. A change in the method of support in conjunction with a change in the direction of rotation of the brake disk can give rise to rattling noises, which tend to irritate an attentive or careful vehicle driver.
The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.